On the causal origin of angular momentum

of dark matter halos and galaxies

With A. Pontzen & H. Peiris: 2012.02201

Corentin Cadiou | Journées du PNCG, Strasbourg

Fall 83 (\(z=0\))

Spiral galaxies \(\leftrightarrow\) high \(J_\star\)

 

3 variables: \(M_\star, J_\star\), morpho.

What causes what?


Some possible scenarios:

  1. Quench then spin down?
  2. Grow & spin down then quench?
  3. Spin down then quench

Galaxy formation & angular momentum

Harrison+17 (KMOS, \(z=1\))

Spiral galaxies \(\leftrightarrow\) high \(J_\star\): also at high-\(z\)

 

\(M_\star, J_\star,M_\mathrm{BH}\), morpho, bulge fraction, …

What causes what?

Rodriguez-Gomez+22 (TNG)

Cosmology & angular momentum

Correlation between environment & galaxy properties (cf previous session!)

Weak lensing signal

Classical model of gal form

1

2

 3 

\(M_\mathrm{DM}, j_\mathrm{DM}, \dots\)

4

\(M_\star, j_\star, \dots\)

Hierarchical clustering

\(N\)-body physics

Accretion of gas
star form, feedback, cooling, ...

Classical model of gal form

1

2

\(M_\mathrm{DM}, j_\mathrm{DM}, \dots\)

4

\(M_\star, j_\star, \dots\)

Hierarchical clustering

\(N\)-body physics

Accretion of gas
star form, feedback, cooling, ...

Part I

 3 

Classical model of gal form

1

2

\(M_\mathrm{DM}\),
\(j_\mathrm{DM}, \dots\)

4

\(M_\star\),
\(j_\star, \dots\)

Hierarchical clustering

\(N\)-body physics

Accretion of gas
star form, feedback, cooling, ...

Part I

Part II

 3 

The origin of DM angular momentum

\(j_\mathrm{DM}\)

Predicting angular momentum

\(z=0\)

\( z = 100\)

Predicting angular momentum

\(z=0\)

\( z = 100\)

\[\mathbf{L}_\mathrm{lin.} \propto \int\mathrm{d}^3q(\mathbf{q}-\bar{\mathbf{q}})\times \nabla\phi\]

Position w.r.t. center

Velocity

[White 84]

\(\mathbf{r}\)\(\times\)\(\mathbf{v}\)

Predicting angular momentum

\(z=0\)

\( z = 100\)

[Porciani+02]

Scatter of 1 dex!

Predicting angular momentum

\(z=0\)

\( z = 100\)

[Genetic modifications: Roth+16, see also Rey&Pontzen 18, Stopyra+20]

Predicting angular momentum

Predicting angular momentum

Predicting angular momentum

  • Angular momentum of individual regions can be predicted accurately.
  • AM of halos ⇒ requires boundaries of patch

\[\mathbf{L}_\mathrm{lin.} \propto \int\mathrm{d}^3q(\mathbf{q}-\bar{\mathbf{q}})\times \nabla\phi\]

[On patch boundaries: see Lucie-Smith+18]

Can we control baryonic
angular momentum?

\(j_\star\)

Can we control baryonic
angular momentum?

Wechsler & Tinker 18

\({\color{red}M_\star} / M_\mathrm{h} \ll \Omega_b / \Omega_m \)
⇒ baryons & DM stem from different regions

Baryons more strongly bound
⇒ less prone to being ejected

[On ≠ patch: see Liao+17]

Numerical setup

Simulations (9Mh @ DiRAC):

  • Resolution \(\Delta x = 35\ \mathrm{kpc}\)
  • \(M_\mathrm{200c} = 10^{12}\ \mathrm{M}_\odot\) @ \(z=2\)
  • Modify \(l(z=2)\)
     
  • SF + AGN & SN feedback (New-Horizon model, Dubois+21)
  • Tracer particles
    Cadiou+19

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

INPUT: Modified at \(z=200\)

OUTPUT:
Measured at \(z=200\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

What drives AM up/down?

PRELIMINARY

PRELIMINARY

Conclusion & outlook

Conclusion & outlook

Questions?
 

More infos in Cadiou+21 (2012.02201)
Cadiou+22 (should appear this week!)

  • angular momentum of DM is predictable
     

  • boundary of halos in the ICs is a hard problem
    ⇒ limits practicality of predictions
     

  • stellar AM can be controlled!
    ⇒ imposed by mergers
    ⇒ controls B/T, \(v/\sigma\), morpho, …
    ⇒ weak lensing predictions easier than expected?
     

⚠️

\(j_\mathrm{DM}\)

⚠️

✅

\(j_\star\)

  • AM of stars originates from initial conditions…
  • can be controlled…
  • \(j_\star\) regulate galaxy disk, bulge, \(v/\sigma\), \(R_{1/2}\)
  • Negligible AGN/SN global self-regulation

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

Temporary conclusions

  • angular momentum is predictable

     

  • boundary of halos in the ICs is a hard problem
    ⇒ limits practicality of predictions (for now)

     

  • baryons appear to be simpler!
    ⇒ good news for weak lensing predictions
    ⇒ key to understand morphology

     

  • but why do some objects grow their AM faster/slower?

Verify that

\[\xi_\mathrm{lin}(r) \sim \left\langle {\color{green}\underbrace{\delta(x=d)}_\mathrm{in}} {\color{purple} \underbrace{\delta(x=d+r)}_\mathrm{out}}\right\rangle \]

is the same in spliced / ref simulation.

Verify that

\[\xi_\mathrm{lin}(r) \sim \left\langle {\color{green}\underbrace{\delta(x=d)}_\mathrm{in}} {\color{purple} \underbrace{\delta(x=d+r)}_\mathrm{out}}\right\rangle \]

is the same in spliced / ref simulation.

Verify that

\[\xi_\mathrm{lin}(r) \sim \left\langle {\color{green}\underbrace{\delta(x=d)}_\mathrm{in}} {\color{purple} \underbrace{\delta(x=d+r)}_\mathrm{out}}\right\rangle \]

is the same in spliced / ref simulation.

Galaxy formation

[L. Cortese; SDSS.]

[Dubois+16]

AGN         no AGN

Origin of morphological diversity at fixed mass?

[L. Cortese; SDSS.]

[Dubois+16]

AGN         no AGN

Origin of morphological diversity at fixed mass?

How to explain environmental effects?

Galaxy formation

[Danovich+15]

The origin of high \(z\) angular momentum

[Danovich+15]

I. Torque with cosmic web

The origin of high \(z\) angular momentum

[Danovich+15]

I. Torque with cosmic web

II. Transport at constant AM

The origin of high \(z\) angular momentum

[Danovich+15]

I. Torque with cosmic web

II. Transport at constant AM

III. Torque down in inner halo

The origin of high \(z\) angular momentum

[Danovich+15]

I. Torque with cosmic web

II. Transport at constant AM

III. Torque down in inner halo

IV. Mixing in inner disk & bulge

The origin of high \(z\) angular momentum

The origin of high \(z\) angular momentum

[Danovich+15]

IV. Mixing in inner disk & bulge

Fraction that ends up in disk vs. IGM?

Influence of galactic physics?

III. Torque down in inner halo

Origin of torque down (pressure or gravity)?

Loss of link with cosmic AM?

II. Transport at constant AM

Same evolution in cold/hot accretion modes?

I. Torque with cosmic web

Predict pre-accretion AM?

Alignment with environment?

The origin of high \(z\) angular momentum

[Danovich+15]

IV. Mixing in inner disk & bulge

Fraction that ends up in disk vs. IGM?

Influence of galactic physics?

III. Torque down in inner halo

Origin of torque down (pressure or gravity)?

Loss of link with cosmic AM?

See Cadiou+21c

II. Transport at constant AM

Same evolution in cold/hot accretion modes?

I. Torque with cosmic web

Predict pre-accretion AM?

Alignment with environment?

The origin of high \(z\) angular momentum

[Danovich+15]

IV. Mixing in inner disk & bulge

Fraction that ends up in disk vs. IGM?

Influence of galactic physics?

III. Torque down in inner halo

Origin of torque down (pressure or gravity)?

Loss of link with cosmic AM?

II. Transport at constant AM

Same evolution in cold/hot accretion modes?

I. Torque with cosmic web

Predict pre-accretion AM?

Alignment with environment?

+

\( R_{1/2} \)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

On the causal origin of the angular momentum of dark matter halos and galaxies

By Corentin Cadiou

On the causal origin of the angular momentum of dark matter halos and galaxies

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